Write and Graph Linear Equation in Slope Intercept

Write and Graph Linear Equation in Slope. Intercept Form I Can: 1)Write equations in slope-intercept form. 2) Graph equations that are written in slopeintercept form.

Review Slope-Intercept Form • Slope-intercept form is written as: y = mx + b SLOPE • Slope: how slanted a line is • Y-intercept: where the line touches the Y-INTERCEPT y-axis

Use a given slope and y-intercept to write an equation in slope intercept form 1) m = 3, b = 4 y = mx + b slope-intercept form y = 3 x + 4 substitute the values given for m and b 2) m = 1 2 , b = -2 y = mx + b slope-intercept form 1 substitute the values given for m and b y= 2 x– 2

Try… Use the given slope and y-intercept to write the equation in slope-intercept form: 2) m = -2, b = 5 3) m = 6, b = -2

Slope-Intercept Form • The slope-intercept form is a way of writing an equation y = mx + b SLOPE Y-INTERCEPT

Identify the slope and y-intercept 1) y = 3 x + 4 2) 1 y=– x– 8 2 3) y = – 5 x – 9 slope: 3 y-intercept: 4 1 2 y-intercept: – 8 slope: – 5 y-intercept: – 9 slope: –

What if the equation is not in slopeintercept form? • Rewrite the equation to fit the form y = mx + b Ex) 2 x + y = 3 -2 x y = -2 x + 3 Slope: -2 Y-Intercept: 3

Try… Rewrite the equation in slope-intercept form and identify slope and y-intercept. 4) 3 x – 3 y = 12 5) x + 4 y = 6

Graph Using Slope-Intercept Form 3 x + y = 2 -3 x Step 1: Step 2: Step 3: Step 4: y = -3 x + 2 Rewrite the equation Identify slope & y-intercept slope: -3 y-intercept: 2 Plot the y-intercept y Use the slope to find the 2 nd point. 0 x

Try… Graph using slope-intercept form. 6) -2 x – y = 5 7) x + 3 y = -9